The most fully developed economic model of individual criminal behavior is Ehrlich (1973). He assumes that both legal employment and apprehension- punishment (consequent upon illegal behavior) are uncertain events and derives his supply of crime function from a model of constrained expected utility maximization. Some limitations to his model are: (1) Non-monetary pleasure from crime enters the model only indirectly and superficially. (2) The occurrence of a crime is assumed to be a decision of the criminal, rather than an uncertain event partially dependent on actions of the public. (3) Ehrlich's model is an a-temporal one-period type which cannot be used to analyze recidivism and its determinants. The objective of my research is to relax the assumptions of that model in order to broaden its generality and potential applicability. Three models will be developed. In the first, in addition to income gain, direct pleasure or displeasure from crime will be allowed for in the offender's preference field and decision function. In the second, uncertainty about the occurrence of the crime itself and the interaction of the behavior of the offender and the public will be analyzed. Thirdly, an inter-temporal model will be developed to analyze career decisions of potential criminals. Emphasis here will be on the effects of on-the-job training and prison training- in both legal and illegal activities - on recidivism and on the initial choice of criminal activities and their levels. In all three models the emphasis of the analysis will be on examining the direction of response to parameters of the models that are under the actual or potential control of the public and its agents. Although these models and the derivation of their implications are intended to stand on their own as a piece of research and be publishable as such, this modelling is also the first phase of a broader examination of the interaction of criminal behavior and the public's direct and indirect responses.